What is the breed of horse that always chesnut?

There isn't a breed of horse that is *always* chestnut.

Chestnut is a coat color, not a breed. While some breeds have a higher prevalence of chestnut horses, it's not exclusive to them. Here's why:

* Genetics: Coat color is determined by multiple genes. Chestnut is caused by a recessive gene, meaning a horse needs two copies of the gene to have a chestnut coat.

* Breed Standards: Some breeds may have a higher number of chestnut horses due to their breeding history or breed standards, but it's never a guarantee.

Examples:

* Thoroughbred: Known for having a variety of coat colors, including chestnut.

* Quarter Horse: Chestnut is common, but other colors like bay, black, and roan are also prevalent.

* Arabian: While they come in various colors, chestnut is a popular and highly valued color in some Arabian lines.

It's important to remember: Even within a breed, there will always be variation in coat color. There's no breed where every horse is guaranteed to be chestnut!